When drilling offshore wells for oil and gas from a rig on a floating vessel, a guide structure is attached to a wellhead housing which is mounted on a conductor pipe usually having a nominal 30 inch diameter. The guide structure usually has four upstanding posts on a six foot radius at the ends of generally horizontal arms. The wellhead housing is landed in and attached to the guide structure and thereafter run to the ocean floor. Removal and replacement of the guide structure is frequently desired.
Operation at a drilling site is interrupted for variable periods of time. When work is temporarily suspended or abandoned for an indeterminate period of time, it is desirable to protect the wellhead.